Akkermansia muciniphila gen. nov., sp. nov. (ATCC BAA-835) has been isolated as a novel strictly anaerobic, mucin-degrading bacterium from a human fecal sample. Cells of strain MucT were oval-shaped (Fig. 3a), showing a different size depending on the medium. In mucin medium, strain MucT was 640 nm in diameter and 690 nm in length and in BHI, strain MucT was 830 nm in diameter and 1μm in length. Cells stained Gram-negative. Flagella were not seen on negatively stained electron micrograph preparations. Formation of spores by the strain was never observed. In mucin medium, the organism could grow as single cells or in pairs, rarely in chains and often formed aggregates.

A. muciniphila grows between 20°C and 40°C with an optimum at 37°C. The pH optimum for growth was 6.5 with a range of 5.5 to 8. Able to grow on gastric mucin, BHI and Columbia media, and on N-acetylglucosamine, N-acetylgalactosamine and glucose when these three sugars are in the presence of 2 g/l of peptone, yeast extract, casitone and tryptone. Cellobiose, lactose, galactose, xylose, fucose, rhamnose, maltose, succinate, acetate, fumarate, butyrate, lactate, casitone, casamino acids, tryptone, peptone, yeast extract, proline, glycine, aspartate, serine, threonine, glutamate do not support growth of the strain. Capable of using mucin as carbon, energy and nitrogen source. The doubling time of the strain was approximately 1.5 hour in mucin medium. 16S rRNA gene sequence analysis revealed that the isolate was part of the division Verrucomicrobia. The closest described relative of strain MucT was Verrucomicrobium spinosum showing 92% sequence similarity. Remarkably, the 16S rRNA gene sequence of strain MucT showed 99% similarity to three uncultured colonic bacteria.

For more details, see Derrien et al., 2004. Int. J. Syst. Evol. Microbiol. 54: 1469-1476.